crypto: jitter - drop kernel-doc notation

Drop "begin kernel-doc (/**)" entries in jitterentropy.c
since they are not in kernel-doc format and they cause
many complaints (warnings) from scripts/kernel-doc.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephan Mueller <smueller@chronox.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>